Dislocation network developed in titanium nitride by ion implantation

Abstract

The present work is concerned with microstructural changes brought about by ion implantation into TiN as-deposited by classical chemical vapor deposition onto cemented carbide substrates. After implantation the ions occupy an implanted zone (IZ) extending to a depth of about 80 nm. The transmission electron microscopy study shows that implantation can lead to the formation of subgrains in the IZ within the original grain structure without changing the grain size. The energy carried by the ions affects the material to far greater depths and a dislocation network is formed below the IZ, termed the implantation affected zone (IAZ). The dislocation density in the IAZ as determined here by x-ray diffraction depends on the total energy carried by the implanted ions. There is a threshold level before a compressive residual stress is developed after which the stress is proportional to the energy, reaching values as high as 3–4 GPa. A mechanism is proposed for the development of the IAZ where an oscillating stress field is developed at the boundary between the IZ and the IAZ and allows the local emission of dislocation fluxes in mezobands into the IAZ.

Surface engineering of Ti–6Al–4V by nitriding and powder alloying using CW CO2 laser

“…66). The variation of hardness of TiN x as a function of N/Ti ratio was shown by Sproul et al 72 for sputtered coatings, to have a narrow range between 3140 and 3400 kg mm 22 , the latter figure also given by Perry et al 73 On the other hand, Munteau and Vaz 74 examining sputtered TiN x films found that the hardness remained constant with a value ,2000 kg mm 22 within the range 45-55 at.-%N. This variation has been explained by Perry et al 75 as due to an indentation size effect, the higher figure associated with the hardness nearer to the surface.…”

Laser surface modification of titanium alloys

“…The variation of hardness of TiN x as a function of N/Ti ratio was shown by Sproul et al (1989) for sputtered coatings, to have a narrow range between 3140 and 3400 kgmm -2 , the latter figure also given by Perry et al (1999). On the other hand, Munteau and Vaz (2006) examining sputtered TiN x films found that the hardness remained constant, with a value about 2000 kgmm -2 within the range 45-55 at% N. This variation has been explained by Perry et al (1999) as due to an indentation size effect, the higher figure associated with the hardness nearer to the surface. To date, it has not been possible to find hardness data related to the stoichiometry of bulk TiN x , over a wide x range.…”

Enhanced Mechanical, Thermal and Electrical Properties of High‐Entropy HfMoNbTaTiVWZr Thin Film Metallic Glass and its Nitrides

“…The increase in hardness can be related to the formation of a new dense dislocation network below the irradiated zone and a reduction in grain sizes can further enhance the hardness of the 30% R N nitride film. [43][44][45][46] It should be noted that the increase in nitrogen in films significantly decreases the disorder caused by ion irradiation. According to the SRIM simulations, a maximum displacement per atom (dpa) is equal to 292 for 0% R N whereas for 30% R N it is 175.…”